Cylinder for a four-cycle internal combustion engine



Aug. 20,1957 WOLF-DIETER BENslNGER 2,803,230

CYLINDER Foa A EouR-cYcLE INTERNAL coNEusEIoN ENGINE med nec. 412. 1955 EnA ,an Mj; n

CYLINDER AFoa A FoURrcYcLE MERNAL coMBUsrroN ENGINE ternal combustion engine and, more particularly, to an engine of the type in which a pair of valves and a recess constituting the mai-n combustion chamber are disposed within the cylinder head.

I't is the object of the present invention to provide a cylinder of the type indicated which results in a highly efficient and smooth combustion of the fuel permitting of 4-a-high compression without risking undue knocking of the engine.

It is a further object of the invention to provide a cylinder head for a four-cycle internal combustion engine in which part of the fuel is injected into a combustion chamber, the balance of the fuel being supplied by carbureting the air sucked into the cylinder.

Further objects of the invention will appear from a detailed description of a preferred embodiment of the invention illustrated in the accompanying drawings, it being understood that such detailed description serves the purpose of illustrating the invention rather than that of restricting or limiting the same. In the drawings,

Fig. l is a longitudinal section taken through the upper part of the jacket and through the lower part of the cylinder head of the engine embodying the present invention, such section being taken along the line I-I 4of Fig. 2, and F Fig. 2 is a bottom view of the cylinder head shown in The cylinder illustrated in Figs. 1 and 2 comprises a water-cooled jacket having a cylindrical bore 11 adapted to accommodate a reciprocatory piston 12 and a cylinder head 13 which is detachably mounted on the jacket 10 and has an end face 14 extending substantially at right angles to the axis 15 of the bore 11. A seal 16 is interposed between the end face 14 of the cylinder head and the top face 18 of the jacket 10 to seal the joint therebetween. The upper dead center position of the plane end face 17 of the piston is disposed in close proximity to the end face 14 of the cylinder head and substantially registers with the top end face 18 of the jacket.

The cylinder head is formed with a recess 19 provided in the end face 14. This recess 19 has a bottom 20 extending substantially parallel to the end face 14. The recess 19 partially overlies the jacket 10 so as to be intersected by a cylindrical surface indicated by the dash-dotted line 21 in Fig. 2 coinciding with the cylindrical bore 11 of the jacket.

A first valve seat 22 is provided in the end face 14 and a second valve seat 23 (Fig. 2) is provided in the bottom of the recess 19. The second valve seat is likewise intersected by the cylindrical surface 21, as will appear from Fig. 2. A pair of valves 24 and 25 is slidably mounted in the cylinder head 13 in parallel relationship to the axis 15 for cooperation with the valve seats 22 and 23. While the valve 23 does not appear in Fig. 1, the location of its axis is indicated by the dash-dotted line 23. The duct 26 terminating at the rst valve seat 22 is preferably the United States Pater C rifice Patented Aug. 20, 1957 "2 inlet duct, whereas the duct (not shown) 'terminating at the second valve seat 23 is preferably the outlet duct.

Moreover, the cylinder head is Vprovided with an ignition chamber 27 which is located laterally of and spaced from the recess 19. This ignition chamber is located substantially above the plane indicated by the dash-dotted line 28 coinciding with the bottom 20 of the recess and is connected therewith by a passageway 29. Moreover, the ignition chamber is equipped with a spark plug 30 and with a fuel-injecting nozzle 31. The recess 19, which at its bottom is partly confined by the top wall 18 of the jacket, constitutes ythe main combustion chamber of the engine. Preferably, the ignition chamber 27 is substantially spherical. The axis 32 of the passageway 29 preferably extends below the center of the ignition chamber 27 at a distance therefrom. This distance may more or less approach the radius of the ignition chamber so that the passageway is disposed more or less tangentially thereto. The passageway 29 communicates with the recess near the bottom 20 thereof and its axis32 vintersects the piston in its upper dead center position below the recess 19. The recess has a side wall 33 which, as shown inFig. 2, extends tangentially Vto the cylindrical surface 21 which coincides with the cylindrical bore 11 of the jacket. Preferably a plane 34 including the axis 32 of the passageway 29 and extending parallel to the axis 15 of the cylindrical bore intersects the first valve seat 22 and is laterally spaced from the second valve seat 23, as will appear from Fig. 2. As indicated in Fig. l, the cylinder head 13 is hollow for Water-cooling purposes in the customary manner.

The wall of the ignition chamber 27 is partly formed by a dished cover plate 35 having a flange 36 bolted to the side wall 37 of the cylinder head 13, the injecting nozzle 31 and the spark plug 30 being mounted on such cover plate 35. Preferably, the axis 38 of the spark plug intersects the center of the spherical ignition chamber 27, whereas the axis 39 of the injecting nozzle 31 intersects the axis 38 at a point located between the opposed wall of the ignition chamber and the center of the latter.

Only part of the fuel required for full power is supplied by means of the injecting nozzle 31. The balance of the fuel is supplied by carbureting the air supplied through the inlet conduit 26. Preferably, the injection of the fuel into the ignition chamber 27 occurs during the compression stroke in which the carbureted air sucked into the cylinder is compressed by the ascending piston 12 preparatory to the ignition initiated by the spark plug 30. The power is preferably controlled by controlling the amount of fuel admixed to the air stream entering through the duct 26, whereas the quantity of fuel injected through nozzle 31 is constant, irrespective of the power produced. In other words, a quantity of fuel that is nearly constant over the entire range of speeds is injected into the ignition chamber 27 by the nozzle 31, such quantity being so chosen as to ensure ignition by the spark plug 30. The descending piston 12 sucks through duct 26 a 4constant quantity of air which is not controlled by any throttle valve. This air is carbureted, however, by an adjustable nozzle with a quantity of fuel commensurate with the required power. The air-fuel mixture sucked into the cylinder is ignited after compression by the ame issuing from the passageway 29 and entering the main combustion chamber constituted by the recess 19.

While the invention has been described in connection with a preferred embodiment thereof, it will be understood that it is capable of further modification, and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains, and as fall within the scope of the invention or the limits of the appended claims.

What I claim is:

1. A cylinder for a four-cycle internal combustion engine comprising a jacket having a cylindrical bore adapted to accommodate a reciprocatory piston, a cylinder head detachably mounted on said jacket and having an end face extending substantially at right angles to the axis of said bore in close proximity to the upper dead center position of said piston and formed with a recess in said end face having a bottom extending substantially parallel to said end face, said recess partially overlying said jacket, a first valve seat being provided in said end face and a second valve seat in said bottom, a pair of valves slidably mounted in said cylinder head in parallel relationship to said axis for cooperation with said valve seats, said cylinder head being further provided with an ignition chamber located laterally of and spaced from said recess and located substantially above a plane coinciding with said bottom and connected with said recess by a passageway, and a spark plug and a fuel-injecting nozzle, both associated with said chamber, said recess constituting the main combustion chamber.

2. A cylinder as claimed in claim 1 provided with an inlet duct terminating at said first valve seat and with an outlet duct terminating at said second valve seat.

3. A cylinder as claimed in claim 1 in which said ignition chamber is substantially spherical.

4. A cylinder is claimed in claim 1 in which an imaginary extension of the cylinder bore intersects said second valve seat provided in said bottom.

5. A cylinder as claimed in claim 1 in which the axis of said passageway extends below the center of said ignition chamber.

6. A cylinder as claimed in claim 1 in which said recess is terminated by a side wall extending substantially tangentially to a cylindrical surface coinciding with said cylindrical bore.

7. A cylinder as claimed in claim 1 in which a plane including the axis of said passageway and extending parallel to the axis of said cylindrical bore intersects said first valve seat and is laterally spaced from said second valve seat.

References Cited in the le of this patent UNITED STATES PATENTS 2,152,037 Fuller Mar. 28, 1939 2,199,706 Mallory May 7, 1940 2,690,741 Broderson Oct. 5, 1954 FOREIGN PATENTS 787,594 France July 8, 1935 

